Present day airliners are compelled to operate with efficient flight plans to meet the ever increasing demands and cope with high fuel prices while sustaining a profitable industry. On the contrary, passenger airplane consume excessive fuel and flight time due to conventional air traffic control procedures. This paper provides an in-depth evaluation on the correlation between flight time and fuel consumption by referring to potential benefits obtained via dynamic programming trajectory optimization. Analytaical solutions on the selection of an optimal cost index based on a series of flight data measured by a commercial GPS receiver are thoroughly discussed. Performance parameters were evaluated using meteorological data of the Japan Meteorological Agency and aircraft performance data of EUROCONTROL. Analytical results show that the selection of descent airspeed and descent rate have a significant influence on reducing the fuel consumption and flight time. Optimal cost index selection was discussed by implementing fuel minimum trajectories and fuel optimal trajectories with arrival time constraints. Analytical results from the proposed model show that current operational procedures let airliners to perform with non-optimal cost indexes to maintain time weighted flight missions which result excessive fuel burn.